A variety of support structures for assisting in manufacturing and fabrication operations are known. A simple worktable with a rigid support framework and a solid upper surface is common. Several worktable configurations are available for use in such processes as assembly, grinding, welding, and the like. However, other processes such as drilling and cutting (e.g., cutting with a circular saw) are more easily performed on a support structure having a support surface with open spaces therein as well as attached clamping means.
A support structure having an upper surface with open spaces suitable for assisting in drilling or cutting through a workpiece may be less common. One solution for fabricators is to lay two or more beams parallel to each other upon a solid surface, e.g., upon a worktable or on the ground. The beams create an open upper work surface suitable for cutting and drilling processes. The beams may be positioned to provide space therebetween and also between the upper work surface provided by the beams and the lower surface on which the beams rest. The open spaces advantageously allow a user to cut or drill through a workpiece without damaging either the tool or the lower surface. While such a method may suffice for some fabricators, laying and using beams on a worktable or the ground may be inconvenient. A worktable may be too small to support the beams securely or too large to be portable. The ground may be wet or dirty, and working on the ground may require a fabricator to kneel in an uncomfortable position. An insufficient amount of space between the upper and lower surfaces may result in damage to the tool and to the lower surface. Using larger beams to create a greater vertical space may create further inconvenience by requiring additional effort to manipulate the larger and heavier beams. In order to support a workpiece such that all portions are fully supported immediately after a severing cut is made, a fabricator would need to use at least four parallel beams, at least two beams under each severed portion. However, it is difficult (if not impossible) to form a coplanar upper work surface with the additional beams, unless the lower surface is almost perfectly flat and the beams are uniform.
Another solution is to use sawhorses. A sawhorse is a portable support structure typically having a narrow top horizontal beam and four divergent legs, physically similar to a trestle. Two sawhorses are used in combination to provide support to a workpiece in two regions thereof with an open space therebetween. A fabricator typically positions the two sawhorses parallel to each other and lays the workpiece thereon, e.g., for sawing with a circular saw. A fabricator generally saws on the side of a sawhorse opposite the other sawhorse rather than between the two sawhorses, allowing the unsupported section of the workpiece to fall to the ground after the cut is made.
While using a pair of sawhorses is helpful when cutting small pieces from a workpiece, this method may result in splintered cuts for larger pieces. Specifically, an unsupported portion may begin to fall before a cut is completed, causing the wood to splinter. In order to make a cleaner cut, several methods of using sawhorses for fully supporting both sides of a workpiece are known and may be advantageous when sawing a large panel of plywood or a long section of lumber. For example, the sawhorses may be arranged in different configurations, such as perpendicular to each other. A “sacrificial piece” may be mounted on top of each sawhorse to provide an enlarged work support surface, where the sacrificial piece may be cut together with the workpiece. However, such methods have disadvantages. Arranging sawhorses perpendicular to each other may increase the difficulty of creating a level and coplanar work surface, and the processes of making, attaching, and replacing “sacrificial pieces” are time consuming and may be inconvenient.
Using more than two sawhorses is sometimes desirable to a fabricator. Additional sawhorses provide extra support to a workpiece and may support it fully on both sides of a cut as a fabricator is sawing. Additional sawhorses may also be arranged in a greater variety of configurations to accommodate workpieces with many shapes and sizes. However, it is typically not feasible to use more than two sawhorses and simultaneously achieve coplanar work supports. Specifically, the top beams of the sawhorses may not be coplanar. As a result, insufficiently supported items may be unstable and may shift during use. Manufacturing processes may be performed with less accuracy. The risk of injury may increase if a dangerous manufacturing process with a sharp tool is performed or if a heavy item falls. One or more sawhorses may even tip over during use, particularly in view of their relatively narrow footprints. The foregoing concerns are especially relevant on many construction sites where flat ground may be difficult to find.
Improved support structures for assisting in such manufacturing processes as drilling and cutting have been developed. For example, U.S. Pat. No. 3,615,087 to Hickman discloses a workbench having a pair of top members in substantially the same plane with a gap therebetween, increasing the convenience of such processes as cutting through lumber. Integral clamping devices are used to open and close the central gap. However, supporting larger workpieces on the Hickman workbench, e.g., supporting a long beam of lumber for a transverse cut where both sides are fully supported both before and after the cut, may be difficult. Clamping a long beam to the work surface for a transverse cut requires additional clamping means and would be inconvenient and time consuming. The overall width of the structure may be adjusted by only a small amount for clamping purposes. Only two support panels, namely the pair of top members, provide the entire surface for supporting a workpiece.
U.S. Pat. No. 5,421,430 to Cox discloses a support structure comprising a collapsible sawhorse having an upper body portion and a plurality of detachably securable legs. An elongated, longitudinally extending gap facilitates such processes as cutting through lumber. Similar to the Hickman workbench, the surface for supporting a workpiece includes only two support panels and may be insufficient for several processes. Also, the width of the device is fixed. While a fabricator may use two or more of the Cox sawhorses of Hickman devices to provide additional work surface, challenges similar to those with standard sawhorses still exist, namely those associated with keeping their support surfaces coplanar.
It would be advantageous to provide an improved support structure for assisting in cutting and drilling, where the structure can accommodate a larger variety of sizes and shapes of workpieces, can provide multiple coplanar work support surfaces, and can comprise a highly portable unit.